diff options
| author | Ben Collins <ben.c@servergy.com> | 2015-04-03 16:09:46 +0000 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2015-04-15 12:10:26 -0400 |
| commit | 0618764cb25f6fa9fb31152995de42a8a0496475 (patch) | |
| tree | 16e5a37e6f584465d05c8df160a81e35609182a8 /drivers/md | |
| parent | 5977907937afa2b5584a874d44ba6c0f56aeaa9c (diff) | |
| download | linux-0618764cb25f6fa9fb31152995de42a8a0496475.tar.bz2 | |
dm crypt: fix deadlock when async crypto algorithm returns -EBUSY
I suspect this doesn't show up for most anyone because software
algorithms typically don't have a sense of being too busy. However,
when working with the Freescale CAAM driver it will return -EBUSY on
occasion under heavy -- which resulted in dm-crypt deadlock.
After checking the logic in some other drivers, the scheme for
crypt_convert() and it's callback, kcryptd_async_done(), were not
correctly laid out to properly handle -EBUSY or -EINPROGRESS.
Fix this by using the completion for both -EBUSY and -EINPROGRESS. Now
crypt_convert()'s use of completion is comparable to
af_alg_wait_for_completion(). Similarly, kcryptd_async_done() follows
the pattern used in af_alg_complete().
Before this fix dm-crypt would lockup within 1-2 minutes running with
the CAAM driver. Fix was regression tested against software algorithms
on PPC32 and x86_64, and things seem perfectly happy there as well.
Signed-off-by: Ben Collins <ben.c@servergy.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-crypt.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index aa1238facbeb..9b5e1eb0ffcf 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -925,11 +925,10 @@ static int crypt_convert(struct crypt_config *cc, switch (r) { /* async */ + case -EINPROGRESS: case -EBUSY: wait_for_completion(&ctx->restart); reinit_completion(&ctx->restart); - /* fall through*/ - case -EINPROGRESS: ctx->req = NULL; ctx->cc_sector++; continue; @@ -1346,10 +1345,8 @@ static void kcryptd_async_done(struct crypto_async_request *async_req, struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); struct crypt_config *cc = io->cc; - if (error == -EINPROGRESS) { - complete(&ctx->restart); + if (error == -EINPROGRESS) return; - } if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq); @@ -1360,12 +1357,15 @@ static void kcryptd_async_done(struct crypto_async_request *async_req, crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); if (!atomic_dec_and_test(&ctx->cc_pending)) - return; + goto done; if (bio_data_dir(io->base_bio) == READ) kcryptd_crypt_read_done(io); else kcryptd_crypt_write_io_submit(io, 1); +done: + if (!completion_done(&ctx->restart)) + complete(&ctx->restart); } static void kcryptd_crypt(struct work_struct *work) |